Something like Gyazo but with a local screenshot manager

Hi, I was wondering if there could be a sidebar panel for taking/managing screenshots. I find 99% of my screenshots are of my browser, and I don't want to have to upload sensitive information located in a screenshot to a service like Gyazo. This sidebar would work something like the notes sidebar, but obviously for screenshots :) I imagine something like this would be HUGELY popular, and would make Vivaldi a much more competitive browser!